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Biomedical subjects

L Harrison

Publications and source records attributed to L Harrison.

At least 109 records · Page 6Linked to original sources

Substance misuse and social work qualifying training in the British Isles: a survey of CQSW courses.

In 1989, all Certificate of Qualification in Social Work (CQSW) courses in the British Isles were included in a survey of the training offered social work students on responding to psychoactive substance misuse. There was a 74% response rate. Eleven per cent of the courses that responded provided no formal substance misuse training. Those that offered training provided a median of 8 hours, with over 70% of students receiving less than 11 hours, indicating that many students were being given the briefest of overviews. Outside of four or five 'centres of excellence', social workers and probation officers training in 1988-89 received less than adequate preparation to work with people with alcohol- and drug-related problems, despite evidence that they account for a large and growing proportion of their caseloads.

Adult↗

Transfection of the Escherichia coli nth gene into radiosensitive Chinese hamster cells: effects on sensitivity to radiation, hydrogen peroxide, and bleomycin sulfate.

The Escherichia coli nth gene encodes endonuclease III, which catalyses the glycolytic removal of various oxidized thymine residues from DNA. A truncated version of nth, with the prokaryotic regulatory sequences removed, was ligated into the retrovirus-based vector pZipneoSV(X)1 and transfected into the radiosensitive Chinese hamster ovary cell line, xrs7. Following selection with G418, two clones (x7nth1 and x7nth6) were shown by Southern analysis to contain the nth gene. No substantial difference in gamma-ray sensitivity was detected between xrs7, clones x7nth1 and x7nth6, and the parent vector transfected clone (x7neo1). However, clones containing the nth gene were more resistant to hydrogen peroxide cytotoxicity [D0's for x7nth1 and x7nth6 were 0.072 microgram/ml (4 microM) and 0.046 microgram/ml, respectively, compared with D0's of 0.034 and 0.027 microgram/ml for xrs7 and x7neo1, respectively] but markedly more sensitive to bleomycin sulfate cytotoxicity than xrs7 and x7neo1 (e.g., 1D0's for x7nth6 and xrs7 were 0.05 and 0.12 microgram/ml, while 2D0's for x7nth1 and xrs7 were 0.35 and 0.48 microgram/ml, respectively). Alterations in sensitivity to hydrogen peroxide and bleomycin sulfate could not be explained by differences in the distribution of the cell-cycle phases and growth rate of nth-containing clones and control cell lines. These results are consistent with the hypothesis that modified thymine lesions are potentially cytotoxic. Hence, when cells incur a high level of endonuclease III-repairable damage relative to strand breakage, such as after treatment with hydrogen peroxide, increased repair capacity increases survival. Gamma radiation produces a lower level of endonuclease III-repairable damage relative to all the other types of lesions produced; hence increased repair capacity has no measurable effect on cell survival. The increased sensitivity of x7nth1 and x7nth6 to bleomycin sulfate toxicity may indicate that, when thymine damage and single-strand breaks are in close proximity on opposite strands of the DNA, endonuclease III, which incises DNA at the site of damaged residues, can increase the number of double-strand breaks and hence decrease the level of cell survival.

Animals↗

Intraoperative brachytherapy alone for incomplete resected recurrent rectal cancer.

In order to determine the impact of intraoperative brachytherapy alone in patients with recurrent rectal cancer who, due to prior pelvic radiation therapy, were ineligible to receive further external beam pelvic radiation, we retrospectively reviewed the records of 36 patients with recurrent rectal cancer who had gross residual disease remaining in the pelvis following biopsy alone or subtotal resection. The median follow-up was 24 months (6-81 months). The median survival was 27 months and the 4 year actuarial survival was 25%. There was a suggestion of lower survival in patients who underwent biopsy alone compared with those who underwent a subtotal resection (21% vs. 34%). The local failure (LF) rate was 22% as the only site of failure and 44% as a component of failure. There was a lower but non-significant LF rate in patients who underwent subtotal resection vs. biopsy alone (33% vs. 66%) and those with an 125I implant volume of less than 40 cm3 vs. greater than or equal to 40 cm3 (39% vs. 100%). Four patients (11%) developed treatment-related severe complications (without evidence of LF). Our data suggest that, although it is not clear that intraoperative brachytherapy impacts on the ultimate survival rate in this group of patients, it does offer reasonable local control with acceptable morbidity. Since local control, in and of itself is an important endpoint in the treatment of rectal cancer, we continue to recommend brachytherapy as part of an overall aggressive approach in patients who are unable to receive pelvic radiation therapy.

Adenocarcinoma↗

Pseudomycins, a family of novel peptides from Pseudomonas syringae possessing broad-spectrum antifungal activity.

A family of peptide antimycotics, termed pseudomycins, has been isolated from liquid cultures of Pseudomonas syringae, a plant-associated bacterium. These compounds were purified using Amberlite XAD-2 and reverse-phase liquid chromatography. Pseudomycin A, the predominant peptide in a family of four, showed selective phytotoxicity, and had impressive activity against the human pathogen Candida albicans. Amino acid, mass spectroscopic, and comparative electrophoretic and chromatographic analyses revealed that the pseudomycins are different from previously described antimycotics from P. syringae, including syringomycin, syringotoxin and syringostatins. Pseudomycins A-C contain hydroxyaspartic acid, aspartic acid, serine, arginine, lysine and diaminobutyric acid. The molecular masses of pseudomycins A-C, as determined by plasma desorption mass spectrometry, are 1224, 1208 and 1252 Da, respectively. Pseudomycin D, on the other hand, has a molecular mass of 2401 Da and is more complex than pseudomycins A-C.

Amino Acids↗

Larynx preservation with combined chemotherapy and radiation therapy in advanced but resectable head and neck cancer.

Forty patients with advanced, resectable squamous cell carcinoma of the larynx, oropharynx, or hypopharynx whose surgery would have required total laryngectomy (TL), were treated with one to three cycles of cisplatin-based chemotherapy before local therapy with the goal of larynx preservation. Clinical complete responses (CRs) or partial responses (PRs) to chemotherapy were seen in 26 of 40 patients (65%). Three patients with primary-site disease unresponsive to chemotherapy underwent resection of the primary lesion and neck dissection followed by radiation therapy (RT). Thirty-seven patients were referred after chemotherapy for RT +/- neck dissection. Thirty-one of 40 patient (78%) were rendered disease-free (no evidence of disease [NED]). With a median follow-up of 49 months (range, 31 to 76), the overall actuarial survival rate for the group was 58% at 2 years and 33% at 5 years. The failure-free survival rate was 42% and 33% at 2 and 5 years, respectively. Seven patients refused recommended TL throughout their course. This may have adversely affected survival results. A greater proportion of patients who achieved a CR or PR to chemotherapy remained disease-free compared with those who achieved less than a PR (P less than .001). Sixteen patients relapsed, 10 with locoregional disease. Six patients underwent TL, either for initial induction failure or at relapse, for an actual larynx-preservation rate of 34 of 40 patients (85%). If the seven patients who refused TL are included, the anticipated preservation rate is 27 of 40 patients (68%). Larynx preservation with combined chemotherapy and radiation is feasible and effective in patients with advanced, resectable squamous cell carcinoma of the head and neck (SCHN). This treatment approach requires a motivated patient, careful patient monitoring, and close interdisciplinary cooperation among oncologists.

Adult↗

An interactive computer graphics system for the design of molded and orthopedic shoe lasts.

The Department of Computer Science at North Carolina State University, with support from the Department of Veterans Affairs and National Aeronautics and Space Administration (NASA) Langley Research Center, has developed an interactive graphics program for the development of shoe lasts from digitized images of feet or digitized images of commercial shoe lasts. The program runs on a Sun 3/260 computer with a TAAC-1 graphics accelerator. The program contains operations for region addition and deletion, techniques for narrowing the ankle area, methods for toe extension, operations to allow for shoe inserts, etc. Once the operations by the user are complete, the program will resample the resulting last in a 512 x 512 array. The user is then allowed to select an error tolerance which will guide a data reduction program to represent the last as Coons patches. These patches are then transmitted to a milling machine which will cut the last.

Computer Graphics↗

Addison's disease.

Addison's disease is an uncommon endocrine condition manifested by a variety of nonspecific symptoms, such as malaise, anorexia and nausea. Symptoms usually do not occur until most of the adrenal gland has been destroyed. Autoimmune disease has surpassed tuberculosis as the primary cause of Addison's disease. Nevertheless, tuberculosis still accounts for a significant proportion of cases. The rapid adrenocorticotropic hormone (ACTH) stimulation test is useful for identifying adrenal insufficiency. Maintenance therapy consists of hydrocortisone and fludrocortisone.

Addison Disease↗

Anti-sperm antibodies in homosexual men: prevalence and correlation with sexual behaviour.

The sera of 60 homosexual males were examined for the presence of antibodies to sperm using an indirect immunobead test (IBT). Six of 60 (10%) had antibodies of IgG isotype; in addition two of the six had antibodies of IgA isotype. The presence of antibodies was associated with the practice of unprotected receptive anal intercourse in the previous six months. Antibodies were not found in homosexual men who were celibate, or who practised only oral intercourse during the same period. There was no correlation between the presence of anti-sperm antibodies and antibodies to human immunodeficiency virus (HIV), or numbers of T lymphocytes. These preliminary results lend support to the hypothesis that antigen presentation in the lower gut may be a source of sensitisation against sperm. The possibility that anti-sperm antibodies may be a marker of receptive anal intercourse merits further investigation.

Adult↗

Norfloxacin use in urinary tract infection by urologists and infectious disease specialists.

One hundred thirty-one patients of urologists and infectious disease specialists were entered into an open trial of norfloxacin in the therapy of urinary tract infections (UTIs). All patients were evaluable for tolerability and 98 were evaluable for efficacy. The patient population in this study was older (mean age 53 years) and had more underlying urogenital disorders (30%) or recent invasive urologic procedures (20%) than the typical patient population with UTIs. Over 50% of the patients had infections due to organisms other than Escherichia coli, including Pseudomonas aeruginosa (14), Klebsiella pneumoniae (5), Enterobacter spp (3) and Group D streptococcus (6). Clinical and bacteriologic cure rates were 90 and 91%, respectively. Side effects occurred in 5 patients and were generally mild.

Administration, Oral↗

Norfloxacin versus trimethoprim-sulfamethoxazole in the treatment of urinary tract infections.

In a controlled, randomized trial of 133 patients with proven urinary tract infections (UTIs), significantly more pathogens were found to be susceptible to norfloxacin than to trimethoprim-sulfamethoxazole (TMP-SMZ) (p less than 0.01). Among patients with pathogens susceptible to both drugs, more of those treated with norfloxacin were cured or improved (p = 0.06). When at least one patient variable, i.e., prior history of therapy, was corrected for, this difference became significant (p = 0.03). Norfloxacin eradicated 11 of 13 infections due to Pseudomonas aeruginosa and 6 of 7 due to enterococci. Five patients treated with norfloxacin and two treated with TMP-SMZ had relapses within 6 weeks. Significantly fewer adverse experiences occurred in patients receiving norfloxacin (p less than 0.01).

Adult↗

Carcinoma of major salivary glands. Recent trends.

We have reviewed a 44-year experience with previously untreated carcinomas arising in major salivary glands to compare 319 patients treated before 1966 with 155 who received therapy between 1966 and 1982. Actuarial analysis indicates that five- and ten-year survival of our more recently treated patients was 80% and 65%, compared with 60% and 50% in patients treated before 1966. Explanation for this includes the higher proportion of patients with less aggressive histologic subtypes seen in recent years, as well as the fact that many of our patients treated before 1966 had surgical procedures considered inadequate by current standards. We also believe that adjunctive radiation oncology enhanced survival, but it could not be proved in this retrospective study. Multivariate analysis confirms that the clinical stage was the most important prognostic variable.

Adenocarcinoma↗

New intraoperative brachytherapy techniques for positive or close surgical margins.

Tumors attached or adjacent to critical structures can often not be completely resected or resected with adequate surgical margins. Sites involving major blood vessels, the paravertebral spaces, or critical abdominal structures often present technical difficulties for standard brachytherapy procedures using I-125 or Ir-192 implants. These techniques allow for a high-dose delivery to the tumor bed with minimal normal tissue toxicity. A relatively simple and accurate method is described using I-125 seeds in Vicryl suture threaded through Gelfoam. These permanent implant procedures with radioactive I-125 seeds effectively treat small residual tumors or suspicious margins where standard brachytherapy techniques may be unsatisfactory and technically difficult to perform.

Adult↗

Remote afterloading intraluminal brachytherapy in the treatment of rectal, rectosigmoid, and anal cancer: a feasibility study.

From 1981 to 1986, 28 patients (27 evaluable) were treated with intraluminal brachytherapy (ILBT) using a remote afterloading technique for persistent or recurrent anal, rectal and rectosigmoid cancers. Eighty-nine percent underwent previous surgery for colorectal cancer. Seventy-seven percent of the patients received external beam irradiation (ERT) as a part of the present treatment. Intraluminal brachytherapy was given with a 2 cm diameter cylinder and the dose per fraction ranged from 440 cGy to 840 cGy at 0.5 cm from the surface of the cylinder. Follow-up ranged from 1 to 74 months with a median of 12 months. Patients were divided into two groups. Group I consisted of 15 patients receiving elective ILBT; Group II: 13 patients with recurrent disease. Seventy-one percent of the patients in Group I and 39% of the patients in Group II achieved local control. The majority of patients tolerated treatment well with only transient reactions. However, three patients (11%) developed grade 3 (G3) complications requiring surgical intervention. Eight patients developed moderate complications--grade 2 (G2)--requiring only conservative treatment. This study has identified several factors which appear to influence the risk of developing complications with this combined treatment, using remote afterloading apparatus, among which are technique of previous external beam irradiation, treatment length, anatomical location, intraluminal brachytherapy fractionation, and total cumulative dose (ERT + ILBT). This experience suggests that intraluminal brachytherapy appears to be an acceptable form of treatment, as a boost to external beam radiation therapy, in the management of rectal and colorectal cancers.

Adult↗

Treatment of primary unresectable carcinoma of the pancreas with I-125 implantation.

Between January 1 1974 and October 31 1987, 98 patients with biopsy proven unresectable adenocarcinoma of the pancreas were treated with I-125 implants during laparotomy. Presenting symptoms were pain (57 patients), jaundice (45 patients), and weight loss (34 patients). All patients underwent laparotomy and surgical staging. Thirty patients had T1NoMo disease, 47 patients had T2-3NoMo disease, and 21 patients had significant regional lymph node involvement (T1-3N1Mo). The surgical procedure performed was biopsy only (16 patients), gastric bypass (36 patients), biliary bypass (49 patients), and partial or total pancreatectomy with incomplete resection (5 patients). The total activity and the number of seeds used were determined from the Memorial Sloan Kettering Cancer Center (MSKCC) nomogram. Stereoshift localization X ray films were taken 3-6 days after operation. The mean activity, minimal peripheral dose (MPD), and volume of the implants were 35 mCi, 13,660 cGy, and 53 cm3, respectively. In addition, 27 patients received postoperative external irradiation and 27 patients received chemotherapy. Postoperative complications were observed in 19 patients. These included post-operative death (1 patient), biliary fistula (4), intraabdominal abscess (4), GI bleeding (3), gastric or small bowel obstruction (6), sepsis (5), and deep vein thrombophlebitis (4). Pain relief was obtained in 37/57 patients (65%) presenting with pain. A multivariate analysis showed that four factors significantly affected survival: T stage, N stage, administration of chemotherapy, and more than 30% reduction in the size of the implant on follow-up films. The median survival for the entire group was 7 months. A subgroup of patients with T1No stage disease who received chemotherapy survived 18.5 months. The indications for I-125 seed implantation in unresectable carcinoma of the pancreas are discussed.

Adenocarcinoma↗